Gas turbine, gas turbine apparatus, and refrigerant collection method for gas turbine moving blades

ABSTRACT

A turbine rotor includes a plurality of moving blades having cooling paths through which a refrigerant flows inside, a plurality of wheels having the moving blades mounted in the outer periphery thereof and at least one spacer member installed between the wheels. The spacer member has a plurality of flow paths through which a refrigerant flows after cooling the moving blades. The plurality of flow paths have flow paths interconnecting to the cooling paths in the moving blades on a first wheel adjacent the spacer member and interconnecting to a space formed on a side wall surface with which a second wheel adjacent the spacer member and the spacer member are in contact.

This is a divisional application of Ser. No. 09/644,770, filed Aug. 24,2000, now U.S. Pat. No. 6,405,538.

BACKGROUND OF THE INVENTION

The present invention relates to a gas turbine for cooling moving bladesusing a refrigerant, a gas turbine apparatus, and a refrigerantcollection method for gas turbine moving blades.

The combustion temperature of a gas turbine has a tendency to increaseyear by year so as to increase the efficiency and particularly themoving blades which are exposed to combustion gas become high intemperature, so that it is necessary to let a refrigerant flow in themand cool them.

As a refrigerant, compressed air extracted from a compressor, vaporgenerated by exhaust heat of combustion gas or the like is used.

To improve the efficiency of a gas turbine, it is important to collectand use a refrigerant after cooling the moving blades of the turbine inaddition to realization of a high combustion temperature. Therefore, theso-called closed circuit cooling structure that the refrigerant flowingpath is a closed circuit, for example, as described in Japanese PatentApplication Laid-Open 8-14064 is variously proposed.

The big problems of a gas turbine having such a closed circuit coolingstructure are the stress due to centrifugal force caused by rotation ofthe gas turbine and the sealing property of the connection of therefrigerant flow paths installed in the configuration member of themoving blades and turbine rotor.

The reason for that the stress due to centrifugal force caused byrotation of the gas turbine comes into a problem is shown below.

The turbine rotor rotates at a very high speed round the center line ofthe turbine, so that remarkable stress due to the centrifugal force isgenerated in the outer periphery. Particularly the wheel has many movingblades in the outer periphery and the operating centrifugal force isextremely large, so that high strength is required. Generally, insidethe configuration member of the turbine rotor, the refrigerant flowpaths and others are installed and hence the configuration members arenot uniform, so that the stress is concentrated at a specific part andthere is the possibility that the strength decreases.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a gas turbine requiringrealization of high efficiency with increased combustion temperaturewhich has high reliability on the stress due to the centrifugal forcecaused by rotation of the gas turbine and high efficiency.

A gas turbine according to the present invention has a turbine rotorwhich includes a plurality of moving blades having cooling paths throughwhich a refrigerant flows inside, a plurality of wheels having theaforementioned moving blades in the outer periphery, and at least aspacer member to be installed between the neighboring wheels, whereinthe spacer member has a plurality of flow paths through which arefrigerant after cooling the moving blades flows and the plurality offlow paths have the first flow paths interconnecting to the coolingpaths installed in the moving blades on the first wheel neighboring withthe spacer members and interconnecting to the first space formed on theside wall surface with which the second wheel neighboring with thespacer member and the spacer member is in contact and the second flowpaths interconnecting to the cooling paths installed in the movingblades on the second wheel and interconnecting to the second spaceformed on the side wall surface with which the first wheel and thespacer member are in contact.

Further, a gas turbine apparatus according to the present invention hasa turbine rotor which includes a plurality of moving blades havingcooling paths through which a refrigerant flows inside, a plurality ofwheels having the aforementioned moving blades in the outer periphery,and at least a spacer member to be installed between the neighboringwheels, a compressor, and a combustor, wherein the spacer member has aplurality of flow paths through which a refrigerant after cooling themoving blades flows and the plurality of flow paths have the first flowpaths interconnecting to the cooling paths installed in the movingblades on the first wheel neighboring with the spacer member andinterconnecting to the first space formed on the side wall surface withwhich the second wheel neighboring with the spacer member and the spacermember are in contact and the second flow paths interconnecting to thecooling paths installed in the moving blades on the second wheel andinterconnecting to the second space formed on the side wall surface withwhich the first wheel and the spacer member are in contact, interconnectthe first and second spaces and the combustion air flow paths suppliedto the combustor to each other, supply compressed air extracted from thecompressor to the moving blades cooling paths as a refrigerant so as tocool the moving blades, collect the refrigerant after cooling the movingblades via the first and second flow paths, and use it as combustion airof the combustor.

A refrigerant collection method for gas turbine moving blades accordingto the present invention is accomplished, in a gas turbine having aturbine rotor which includes a plurality of moving blades having coolingpaths through which a refrigerant flows inside, a plurality of wheelshaving the aforementioned moving blades in the outer periphery, and atleast a spacer member installed between the neighboring wheels, by thatin the moving blades installed in the first wheel neighboring with thespacer member on the upstream side of gas flow, a refrigerant passinginside is introduced in from the upstream side of gas flow andintroduced out on the downstream side of gas flow, and the refrigerantintroduced out from the moving blades is introduced out and collected inthe first cavity formed in the junction surface of the second wheelneighboring on the downstream side of gas flow of the spacer member andthe spacer member via the first flow paths formed in the spacer memberand in the moving blades installed in the second wheel, a refrigerantpassing inside is introduced in from the downstream side of gas flow andintroduced out on the upstream side of gas flow, and the refrigerantintroduced out from the moving blades is introduced out and collected inthe second cavity formed in the junction surface of the first wheel andthe spacer member via the second flow paths formed in the spacer member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing the first embodiment of a gas turbine apparatusof the present invention.

FIG. 2 is a view of the spacer member of the first embodiment which isviewed from the front of the rotation axis.

FIG. 3 is a view of the spacer member of the first embodiment which isdeveloped from the outer periphery surface.

FIG. 4 is a view showing another embodiment of a gas turbine apparatusof the present invention.

FIG. 5 is a view showing still another embodiment of a gas turbineapparatus of the present invention.

FIG. 6 is a view showing a further embodiment of a gas turbine apparatusof the present invention.

FIG. 7 is a view showing a still further embodiment of a gas turbineapparatus of the present invention.

FIG. 8 is a schematic view of a gas turbine apparatus of the presentinvention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The embodiments of the present invention will be explained hereunderwith reference to the accompanying drawings.

FIG. 1 shows a part of a section of a gas turbine apparatus of a firstembodiment of the present invention in the axial direction of a turbinerotor.

The constitution of the gas turbine apparatus relating to the firstembodiment will be described hereunder, referring to FIGS. 1 to 3.

In a turbine rotor 3, from the upstream side of gas flow along thelongitudinal direction of the rotating shaft, a disk-shaped first stagewheel 1, a circular first stage spacer member 4, and a disc-shapedsecond stage wheel 2 are sequentially arranged and the wheels 1 and 2and the spacer member 4 are mutually connected and integrated by bolts11 passing through them. Namely, between the first stage wheel 1 and thesecond stage wheel 2 which are neighboring wheels among a plurality ofwheels, the spacer member 4 is arranged. When the wheels are taken intoaccount, the first stage wheel 1 and the second stage wheel 2 areneighboring with each other. “Neighboring” of the wheels which isreferred to as here means “adjacent” and actually, they may be incontact with each other or not.

In the outer periphery of the first stage wheel 1, a plurality of firststage moving blades 7 each having a cooling path 7 a inside respectivelyare installed in a ring-shape and in the same way, in the outerperiphery of the second stage wheel 2, a plurality of second stagemoving blades 8 each having a cooling path 8 a inside respectively areinstalled in a ring-shape.

The first stage spacer member 4 has flow paths 5 and 6 inside throughwhich a refrigerant after cooling the moving blades passes.

In a junction surface 1 a of the first stage spacer member 4 and thefirst stage wheel 1 positioned on the upstream side of gas flow of thefirst stage spacer member 4, a hollowed refrigerant collection cavity 9on the upstream side is formed and in a junction surface 2 a of thefirst stage spacer member 4 and the second stage wheel 2 positioned onthe downstream side of gas flow of the first stage spacer member 4, ahollowed refrigerant collection cavity 10 on the downstream side is alsoformed.

The flow paths 5 for letting a refrigerant after cooling the movingblades flow, each of which is installed in the first stage spacer member4, interconnect the cooling paths 7 a installed in the first stagemoving blades 7 on the upstream side of gas flow and the refrigerantcollection cavity 10 on the downstream side, respectively and the flowpaths 6 interconnect the cooling paths 8 a installed in the second stagemoving blades 8 on the downstream side of gas flow and the refrigerantcollection cavity 9 on the upstream side, respectively.

The flow paths 5 and 6 have, in the positions slightly close to thecenter of the spacer member 4 from spacer arms 21, bent parts 5 a and 6a and are formed so as to extend in parallel with the rotating shaftbetween the connection of the moving blades and the spacer member 4 andthe bent parts 5 a and 6 a.

The flow paths 5 and 6 between the bent parts 5 a and 6 a and therefrigerant collection cavities 9 and 10 each take the configurationpassing through linearly as shown in FIG. 1. However, it may be formedin a curved shape and it may be decided in consideration of theworkability.

In this case, the spacer arms 21 are the parts where in the outerperiphery of the first stage spacer member 4, the refrigerant collectioncavities 9 and 10 are formed on the inner periphery side thereof.

On a side 1 b of the first stage wheel 1 on the upstream side of gasflow, a hollowed refrigerant supply cavity 18 is formed and in the sameway, on a side 2 b of the second stage wheel 2 on the downstream side ofgas flow, a hollowed refrigerant supply cavity 19 is formed. Therefrigerant supply cavity 18 is interconnected to the cooling paths 7 aof the moving blades 7 via a path 1 c inside the first stage wheel 1 andthe refrigerant supply cavity 19 is interconnected to the cooling paths8 a of the moving blades 8 via a path 2 c inside the second stage wheel2.

According to this embodiment, the parts referred to as the refrigerantsupply cavities 18 and 19 or the refrigerant collection cavities 9 and10 represent spaces or flow paths for distributing or collecting arefrigerant for each moving blade. The refrigerant supply cavities 18and 19 and the refrigerant collection cavities 9 and 10 each may beformed as one space or flow path along the overall periphery in thecircumferential direction of the turbine rotor 3 or may be divided intosome parts.

Around the rotating shaft on the inner periphery side from therefrigerant supply cavities 18 and 19 or the refrigerant collectioncavities 9 and 10 of the turbine rotor 3, a plurality of refrigerantsupply pipes 12 and a plurality of refrigerant collection pipes 13 areindependently arranged.

The refrigerant supply pipes 12 pass through the first stage wheel 1,the first stage spacer 4, and the second stage wheel 2 and a refrigerantintroduced from other than the turbine rotor system passes through thesecond stage wheel 2, the first stage spacer 4, and the first stagewheel 1 sequentially from the downstream side of gas flow.

On the side 1 b of the first stage wheel 1 on the upstream side of gasflow and the side 2 b of the second stage wheel 2 on the downstream sideof gas flow, refrigerant supply slits 14 and 15 are formed respectivelyand interconnect the refrigerant supply pipe 12 to the refrigerantsupply cavities 18 and 19. If the refrigerant supply slits 14 and 15practically introduce a refrigerant distributed from the refrigerantsupply pipe 12 to the refrigerant supply cavities 18 and 19, any shapeand number of slits can be taken.

If the refrigerant supply pipe 12 can practically distribute arefrigerant introduced from other than the turbine rotor system to therefrigerant supply slits 14 and 15, the arrangement in the turbinerotor, the shape and number of pipes, and the number of wheels andspacer members through which a refrigerant passes are no particularobject. For example, a refrigerant may be introduced from the upstreamside of gas flow of the turbine rotor 3 and may pass throughsequentially the first stage wheel 1, the first stage spacer 4, and thesecond stage wheel 2.

A plurality of the refrigerant supply pipes 12 may be interconnected toboth or either of the refrigerant supply slits 14 and 15 according tothe flow rate of a refrigerant to be supplied to the moving blades 7 and8 from the wheels 1 and 2.

The refrigerant collection pipe 13 passes through the first stage wheel1 and the first stage spacer member 4 and introduces a collectionrefrigerant after cooling the moving blades to other than the turbinerotor system from the upstream side of gas flow of the turbine rotor 3.

On a side 4 a of the first stage spacer member 4 on the upstream side ofgas flow and a side 4 b on the downstream side of gas flow, refrigerantcollection slits 24 and 25 are formed respectively and interconnect therefrigerant collection cavities 9 and 10 to the refrigerant collectionpipe 13. If the refrigerant collection slits 24 and 25 practicallyintroduce collected refrigerants 17 a and 16 a after cooling the movingblades from the refrigerant supply cavities 18 and 19 to the refrigerantcollection pipe 13, the shape and number of slits are no particularobject.

If the refrigerant collection pipe 13 can practicaily collect therefrigerants 16 a and 17 a after cooling the moving blades from therefrigerant collection slits 24 and 25 and introduce them outside theturbine rotor system, in the same way as with the refrigerant supplypipe 12, the arrangement in the turbine rotor, the shape and number ofpipes, and the numbers of wheels and space members through which arefrigerant passes are no particular object. For example, a refrigerantmay flow through sequentially the first stage spacer member 4 and thesecond stage wheel 2 and may be introduced outside the turbine rotorsystem from the downstream side of gas flow of the turbine rotor 3.

A plurality of refrigerant collection pipes 13 may be interconnected toboth or either of the refrigerant collection slits 24 and 25 accordingto the flow rate of a refrigerant to be collected from the moving blades7 and 8 of the wheels 1 and 2.

The constitution of the gas turbine apparatus of this embodiment will besupplementally explained additionally by referring to FIGS. 2 and 3.

FIG. 2 shows a part of the first stage spacer member 4 of the gasturbine apparatus shown in FIG. 1 which is viewed from the upstream sideof the revolving shaft.

A plurality of flow paths 5 and 6 are installed alternately andindependently in the outer periphery of the spacer member 4 and arrangedfor each moving blade so that the flow paths 5 are connected to thecooling path outlet 7 b of the first stage moving blades 7 and the flowpaths 6 are connected to the cooling path outlet 8 b of the second stagemoving blades 8.

The flow paths 5 are interconnected to the refrigerant collection cavity10 installed in the outer periphery of the first stage spacer member 4corresponding on the back side of the sheet of FIG. 2 and the flow paths6 are interconnected to the refrigerant collection cavity 9 installed inthe outer periphery of the first stage spacer member 4.

The refrigerant collection cavity 9 may be formed along the overallperiphery in the circumferential direction of the first stage spacermember 4 or may be divided into some parts.

The refrigerant collection slit 24 is formed on the side of the firststage spacer member 4 in the radial direction and interconnects therefrigerant collection cavity 9 to the refrigerant collection pipe 13installed around the revolving shaft of the turbine rotor 3.

Around the revolving shaft of the turbine rotor 3, the bolt 11, therefrigerant supply pipes 12, and the refrigerant collection pipes 13 arearranged independently and a plurality of first stage spacer members 4are installed respectively.

FIG. 3 is the section A-A′ shown in FIG. 2 which is developed in a planeshape viewed from the outer periphery of the spacers. The refrigerantcollection paths 5 and 6 are formed alternately and linearly and do notintersect each other inside the spacers.

Next, the flow of a refrigerant for cooling the moving blades of the gasturbine apparatus of this embodiment will be explained hereunder. Inthis embodiment, an example using compressed air extracted from thecompressor of the gas turbine apparatus as a refrigerant is indicated.

A refrigerant extracted from a compressor 30 (refer to FIG. 8 forexample) passes through an extracted air refrigerant path 36 (refer toFIG. 8 for example) outside the turbine rotor system and is introducedinto a plurality of refrigerant supply pipes 12 installed around therevolving shaft of the turbine rotor. A refrigerant introduced into therefrigerant supply pipes 12 is distributed to a plurality of refrigerantsupply slits 14 and 15 formed in the side 1 b on the upstream side ofgas flow of the first stage wheel 1 and the side 2 b on the downstreamside of gas flow of the second stage wheel 2.

Refrigerants passing through the refrigerant supply slits 14 and 15 aredistributed in the circumferential direction of the turbine rotor 3 inthe refrigerant supply cavities 18 and 19. Then, they pass through thepath 1 c of the first stage wheel 1 and the path 2 c of the second stagewheel 2 and are introduced into the cooling paths 7 a and 8 a of themoving blades 7 and 8 installed in the outer peripheries of the firststage wheel 1 and the second stage wheel 2.

The flow of refrigerants in the moving blades 7 and 8 is respectivelyrepresented by arrows 16 and 17 shown in FIG. 1 and at this time, therefrigerants cool the moving blades 7 and 8 getting high in temperatureby combustion gas flowing outside.

The refrigerants 16 a and 17 a after cooling the moving blades arerespectively introduced into the flow paths 5 and 6 independentlyinstalled in the first stage spacer member 4 from the moving blades 7and 8. In this case, the refrigerant 16 a having cooled the first stagemoving blades 7 is introduced into the flow path 5 and the refrigerant17 a having cooled the second stage moving blades 8 is introduced intothe flow path 6.

The refrigerant 16 a passing through the flow paths 5 is introduced tothe refrigerant collection cavity 10 on the downstream side and therefrigerant 17 a passing through the flow paths 6 is introduced to therefrigerant collection cavity 9 on the upstream side.

Furthermore, the refrigerants 16 a and 17 a flow into the refrigerantcollection pipes 13 arranged around the rotating shaft of the turbinerotor 3 via a plurality of refrigerant collection slits 24 and 25 formedin the sides 4 a and 4 b of the first stage spacer member 4 in theradial direction from the refrigerant collection cavity 10 on thedownstream side and the refrigerant collection cavity 9 on the upstreamside. The refrigerants reached the refrigerant collection pipes 13 areintroduced outside the turbine rotor system and supplied to combustionair of the combustor 31(refer to FIG. 8 for example) finally via acollection refrigerant path 37 (refer to FIG. 8 for example) installedoutside the turbine rotor system.

The effects obtained by the actual operation using the aforementionedconstitution of this embodiment will be explained hereunder.

The first effect of this embodiment is that reliable wheels can beobtained based on the stress by the centrifugal force caused by therotation of the gas turbine.

As the gas turbine increases in rotation, the centrifugal force actingon the first stage wheel 1, the second stage wheel 2, and the firststage spacer member 4 constituting the turbine rotor 3 increases. Sincethe wheels particularly have the moving blades 7 and 8 planted therein,remarkable stress is acted on the outer periphery of each of the wheels.

If the outer peripheries of the wheels 1 and 2 are structured so as tohave many refrigerant flow paths, no sufficient strength can be obtainedand there is the possibility that the stress is concentrated on theperipheral part of the refrigerant flow path. Furthermore, when there isa flow path of a refrigerant having become high in temperature aftercooling the moving blades, the refrigerant directly comes in contactwith the wheels to raise the temperature of the wheels, so that it isnecessary to consider the allowable stress of the wheels.

According to this embodiment, since the refrigerant flow paths installedin the first stage wheel 1 and the second stage wheel 2 are only thepaths 1 c and 2 c of a refrigerant at a low temperature before coolingthe moving blades, the structure is simple and the effect on a reductionin the allowable stress of the wheel member due to temperature rise issmall and hence wheels high in strength and reliable on the stress dueto centrifugal force and thermal stress can be obtained.

The second effect of this embodiment is that a reliable spacer membercan be obtained for the stress by the centrifugal force caused by therotation of the gas turbine.

As the centrifugal force caused by the rotation of the gas turbineincreases, on the spacer arms 21 of the first stage spacer member 4shown in FIGS. 1 and 3, bending stress is generated outward in theradial direction and as the number of revolutions increases, the bendingstress increases, so that it is necessary to consider this stress.

On the other hand, according to this embodiment, on the bent parts 5 aand 6 a of the flow paths installed in the spacer member 4, bendingstress is not easy to act because they are not on the spacer arms 21 andthe stress acting on the bent parts of the flow paths reduces. Theradius of curvature at the bent parts 5 a and 6 a of the flow paths islarger than that when, for example, the cooling paths 7 a of the firststage moving blades 7 are interconnected to the refrigerant collectioncavity 9 on the upstream side and the cooling paths 8 a of the secondstage moving blades 8 are interconnected to the refrigerant collectioncavity 10 on the downstream side. As a result, the stress concentrationis moderated. Therefore, not only for the first stage wheel 1 and thesecond stage wheel 2 but also for the first stage spacer member 4, thereliability for the stress by the centrifugal force caused by therotation of the gas turbine is high.

The third effect of this embodiment is that the sealing property at theconnection of the cooling paths in the moving blades and the refrigerantflow paths installed in the spacer member is high.

As mentioned above, when a refrigerant leaks in combustion gas, thecombustion gas temperature lowers and the turbine efficiency reduces, sothat it is necessary to keep the sealing property at the connection withthe refrigerant flow paths high. Particularly since the turbine rotorrotates at high speed at a high temperature, it is important to take ashape that deformation due to heat and centrifugal force under theactual operation condition is not easily caused and the sealing propertyis high.

If the refrigerant path outlets 7 b and 8 b of the moving blades 7 and 8directly face the space having a spread of the refrigerant collectioncavities 9 and 10, peripheries 4 c and 4 d of the spacer member 4 incontact with the moving blades 7 and 8 have lower structural strengthand the deformation due to centrifugal force is easily increased.Furthermore, the contact area of the moving blades with the spacermember 4 is small and it is necessary to consider leakage of arefrigerant from the peripheries 4 c and 4 d of the spacer member 4.

Therefore, in the aforementioned embodiment or the present invention,the flow paths 5 and 6 of a refrigerant after cooling the moving bladesinstalled in the space member 4 are independently installed at each ofthe moving blades cooling path outlets 7 b and 8 b, so that the strengthof the peripheries 4 c and 4 d in contact with the moving blades of thespacer member 4 is high and the deformation due to centrifugal force canbe made smaller. Furthermore, since the contact area of the movingblades 7 and 8 with the spacer member 4 is large, the sealing propertyat the connection of the moving blades cooling path outlets 7 b and 8 bwith the flow paths 5 and 6 installed in the spacer member 4 can be kepthigh.

In addition, this embodiment produces an effect such that the effect ofheat on the strength of the wheels can be reduced. Namely, since thereare no flow paths of a refrigerant having high in temperature aftercooling the moving blades in the wheels, the wheels cannot be easilyheated, and the reduction in the allowable stress due to temperaturerise is suppressed, and the strength can be kept high. At the same time,the temperature incline between the high-temperature portion and thelow-temperature portion in the wheel member is not easily increased, sothat the effect of the thermal stress acting on the wheels can bereduced.

As mentioned above, according to this embodiment, high-strength wheelscan be obtained and the stress concentration due to the centrifugalforce acting on the wheels and spacer member can be reduced, so that areliable gas turbine can be provided. Furthermore, the sealing propertyat the connection of the moving blades cooling paths with the flow pathsinstalled in the spacer member can be improved, so that the refrigerantleakage is suppressed and the high efficiency can be realized.

FIG. 4 shows a part of the section of a gas turbine apparatus of thesecond embodiment of the present invention in the axial direction of theturbine rotor. The explanation of the constitution and operation commonto those of the first embodiment will be omitted.

According to this embodiment, the bent parts 5 b and 6 b of the flowpaths 5 and 6 installed in the spacer member 4 are formed in theneighborhood of the center of the spacer member 4 in the axialdirection.

The neighborhood of center of the spacer member 4 in the axial directionis a location which is most hard to be adversely affected by the bendingstress acting on the spacer arms 21 by the centrifugal force, so thatthe stress acting on the neighborhood of the bent part is made smaller.Therefore, no stress concentration is generated in the neighborhood ofthe bending part of each of the flow paths and there is an advantagethat a reliable spacer member can be obtained for the stress due to thecentrifugal force.

FIG. 5 shows a part of the section of a gas turbine apparatus of thethird embodiment of the present invention in the axial direction of theturbine rotor. The explanation of the constitution and operation commonto those of the first embodiment will be omitted.

In this embodiment, the flow paths 5 c and 6 c installed in the spacermember 4 are arranged generally linearly. Therefore, there are no bentparts in the flow paths, so that no stress concentration is generated ata specific part of the flow paths and a reliable spacer member can beobtained for the stress due to the centrifugal force.

FIG. 6 shows a part of the section of a gas turbine apparatus of thefourth embodiment of the present invention in the axial direction of theturbine rotor. The explanation of the constitution and operation commonto those of the first embodiment will be omitted.

In this embodiment, spacers 22 are arranged so as to divide therefrigerant collection cavities 9 and 10 into spaces 9 b and 10 b on theside of the first stage spacer 4 and spaces 9 a and 10 a on the side ofthe first stage wheel 1 and the second stage wheel 2 in the overallcircumferential direction.

When a high temperature refrigerant after cooling the moving blades isdirectly blown onto refrigerant collection cavity surfaces 1 d and 2 dof the wheels 1 and 2 and the temperature rises, the allowable stress ofthe wheel member reduces and hence the strength is easily decreased.Between the comparatively lower-temperature refrigerant supply cavities18 and 19 installed on the opposite sides 1 b and 2 b of the wheels 1and 2, a temperature difference is generated and great thermal stress iseasily generated in the wheels. The parts with the wheel cavities formedare in the outer peripheries of the wheels and the moving blades areinstalled there, so that there are locations having large stress due tocentrifugal force. As a result, the thermal effect and the effect ofstress due to centrifugal force are overlaid, so that it is necessary toconsider the reliability.

Therefore, in this embodiment, the spacer plates 22 isolate therefrigerant collection cavity surfaces 1 d and 2 d of the wheels 1 and 2from the high temperature refrigerants 16 a and 17 a after cooling themoving blades and hence moderate the thermal effect on the wheels 1 and2. Therefore, it can be prevented that the wheels 1 and 2 become warmand the allowable stress reduces and at the same time, the thermalstress acting on the wheels 1 and 2 can be reduced, so that thereliability of the wheels 1 and 2 is improved more.

If on the junction surface of the wheels 1 and 2 with the spacer member4, the refrigerant collection cavities 9 and 10 are entirely dividedinto the spaces 9 a and 10 a on the wheel side and the spaces 9 b and 10b on the spacer member side respectively by the spacer plates 22, theshape of the spacer plates 22 is no particular object. For example, thespacer plates may be formed in a ring shape that the overall peripheryis integrated or combined with some members. As a material of the spacerplates 22, a heat-resistant material is suited and the surface of ametallic material may be covered with a heat-resistant material such asceramics or chrome carbide.

The fourth embodiment has a constitution that the refrigerant collectioncavities 9 and 10 are divided by the spacer plates 22 and the cavitysurfaces 1 d and 2 d of the wheels 1 and 2 are isolated from the hightemperature refrigerants 17 a and 16 a after cooling the moving blades.However, in addition to it, a constitution that the surface of eachmember through which a high temperature refrigerant passes such as thecavity surfaces 1 d and 2 d of the wheels 1 and 2 and the surfaces ofthe refrigerant collection slits 24 and 25 is coated and insulated fromheat may be used. In this case, as a coating material, a heat-resistantmaterial such as ceramics or chrome carbide or a porous material issuited.

FIG. 7 shows a part of the section of a gas turbine apparatus of thefifth embodiment of the present invention in the axial direction of theturbine rotor. The explanation of the constitution and operation commonto those of the first to fourth embodiments will be omitted.

In this embodiment, at a connection 23 a of the flow path 5 installed inthe spacer member 4 and the cooling path outlet 7 b of the moving blades7, a sealing material 23 is installed. Also at the connection of theflow path 6 not shown in the drawing and the cooling path outlet 8 b ofthe moving blades 8, a sealing material 23 is installed.

If the refrigerant path outlet of the moving blades directly faces thespace having a spread of the refrigerant collection cavity, it isnecessary to consider the sealing property in correspondence with thedeformation of the moving blades and spacer member by heat orcentrifugal force.

According to the first to fourth embodiments, the flow paths 5 and 6installed in the spacer member 4 and the moving blades cooling pathoutlets 7 b and 8 b are formed so as to be interconnected in one-to-onecorrespondence, so that when the sealing member 23 is installed at theconnection 23 a as indicated in the fifth embodiment, the sealingproperty can be easily improved. Therefore, the leakage of a refrigerantcan be prevented and the turbine efficiency can be kept high. Thisembodiment indicates an example that annular sealing materials 23 inaccordance with the flow path 5 installed in the spacer member 4 and theopening shape of the cooling path outlet 7 b of the moving blades 7 areinserted into a pair of connections 23 a one by one. However, othermethods are also available. For example, some annular sealing materialsto be inserted into a pair of connections 23 a may be integrated and ifthe sealing property can be practically exhibited, the shape andmaterial thereof are no particular object.

FIG. 8 shows an embodiment of a gas turbine of the present invention.For the constitution and operation described in the previous embodiment,the explanation will be omitted.

The turbine rotor 3 that a plurality of wheels 34 and a plurality ofspacer members 35 are integrated by bolts 11 and the compressor 30 arearranged on the center line 33 of the turbine, and fuel 32 is mixed withcombustion air compressed by the compressor 30 by the combustor 31, andobtained high temperature combustion gas is introduced into the turbine38.

According to this embodiment, compressed air taken out from thecompressor 30 is introduced into the turbine rotor system via theextraction refrigerant path 36 and used as a moving blade coolingrefrigerant.

The extraction refrigerant path 36 is connected to the refrigerantsupply pipes 12 in the turbine rotor system and compressed air issupplied to the moving blade cooling paths 7 a and 8 a via the pathsdescribed in the first to fifth embodiments.

Compressed air collected in the turbine rotor system after cooling themoving blades is introduced outside the turbine rotor system via therefrigerant collection paths 13 described in the first to fifthembodiments, sent to the combustor 31 via the collection refrigerant 37,and used as a part of combustion air.

By doing this, even if combustion gas becomes high in temperature, themoving blades can be sufficiently cooled and a refrigerant becoming warmby heat exchange can be used as a part of combustion air, so that anefficient gas turbine can be obtained.

As a refrigerant, in addition, a gaseous body such as vapor, nitrogen,and hydrogen and a liquid such as water can be considered and forexample, vapor which is generated using exhaust heat of combustion ofthe gas turbine can be applied.

As mentioned above, according to the present invention, in a gas turbinethat the combustion temperature is increased and realization of highefficiency is required, an effect that a reliable and efficient gasturbine can be realized for the stress due to the centrifugal forcecaused by rotation of the gas turbine can be produced.

What is claimed is:
 1. A turbine rotor including a plurality of movingblades having cooling paths through which a refrigerant flows inside, aplurality of wheels having said moving blades mounted in the outerperiphery thereof, and at least a spacer member installed between saidwheels, wherein said spacer member has a plurality of flow paths throughwhich a refrigerant flows after cooling said moving blades, and saidplurality of flow paths have flow paths interconnecting to said coolingpaths in said moving blades on a first wheel adjacent said spacer memberand interconnecting to a downstream space formed on a side wall surfacewith which a second wheel adjacent said spacer member and said spacermember are in contact.
 2. A turbine rotor according to claim 1, whereinsaid plurality of flow paths have further flow paths interconnecting tosaid cooling paths in said moving blades on said second wheel andinterconnecting to a space formed on a side wall surface with which saidfirst wheel and said spacer member are in contact, and wherein arefrigerant after cooling said moving blades on said first wheel flowsinto said space on a side of said second wheel, and a refrigerant aftercooling said moving blades on said second wheel flows into said space ona side of said first wheel.
 3. A turbine rotor including a plurality ofmoving blades having cooling paths through which a refrigerant flowsinside, a plurality of wheels having said moving blades mounted in theouter periphery thereof, and at least a spacer member installed betweensaid wheels, wherein said spacer member has a plurality of flow pathsthrough which a refrigerant flows after cooling said moving blades, andsaid plurality of flow paths have flow paths interconnecting to saidcooling paths in said moving blades on a first wheel adjacent saidspacer member on an upstream side of gas flow in said turbine and a sideof said spacer member on a downstream side of said gas flow and allowinga refrigerant to flow through said flow paths from said cooling paths insaid moving blades on said first wheel to said side of said spacermember on the downstream side of said gas flow.
 4. A turbine rotoraccording to claim 3, wherein said plurality of flow paths have furtherflow paths interconnecting to said cooling paths in said moving bladeson said second wheel and interconnecting to a side of said spacer on aside of said first wheel, and wherein a refrigerant after cooing saidmoving blades on said first wheel flows into said side of said spacer onthe side of said second wheel, and a refrigerant after cooling saidmoving blades on said second wheel flows into said side of said spacermember on the side of said first wheel.
 5. A turbine rotor including aplurality of moving blades having cooling paths through which arefrigerant flows inside, a plurality of wheels having said movingblades mounted in the outer periphery thereof, and at least a spacermember installed between said wheels, wherein said spacer member has aplurality of flow paths through which a refrigerant flows after coolingsaid moving blades, said plurality of flow paths have first flow pathsinterconnecting to said cooling paths in said moving blades on a firstwheel and a side of said spacer member on a downstream second wheelside, and second flow paths interconnecting to said cooling paths insaid moving blades on a second wheel and a side of said spacer member ona first wheel side, and wherein interconnecting portions of said firstflow paths to said side of said spacer member on the second wheel sideare positioned downstream of interconnecting portions of said secondflow paths to said side of said spacer member on the first wheel side,with respect to a gas flow direction.